Device for drawing metal bars



Dec. 22, 1953 J. R. TSCHUDNOWSKY 2,663,411

DEVICE FOR DRAWING METAL BARS Filed Nov. 29, 1950 5 Sheets-Sheet l 5 17 Z5 /6 I3 I30- 7 F|g.1 m P Fig. 2

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DEVICE FOR DRAWING METAL BARS Filed Nov. 29, 1950 3 Sheets-Sheet 2 Mills/v70? 36 J64 ROGER TSC VUfl/VO WS/f) Dec. 22, 1953 J. R. TSCHUDNOWSKY DEVICE FOR DRAWING METAL BARS 3 Sheets-Sheet 3 Filed NOV. 29, 1950 FIG. 7

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A TIOR/VE' Y5 Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE 2,663,411. DEVICE FOR DRAWING METAL BARS Jean R. Tschudnowsky, Paris, France, assignor to Compagnie Generale du Duralumin et du Ouivre, Paris, France, a corporation of France Application November 29, 1950, Serial No. 198,083

Claims.

My invention relates to the drawing, usually cold, of metal pieces.

It is known that to facilitate the insertion into dies or draw plates of metal bars or other pieces,

for the purpose of drawing them, the usual practice has been to first shape, as by tapering, one end which is called the tang.

It is known, for the purpose of accelerating the drawing operation, to have the drawing benches equipped with devices permitting the insertion of the metal bars or pieces to be drawn into the dies or draw plates by simple pushing, thus avoiding the preliminary step of shaping one end to form a tang.

The present invention relates to the arrange ment of such drawing benches, and has for an object to still further increase their productive capacity.

Another object of the present invention is to provide a device for drawing metal bars or pieces without preliminary shaping thereof, wherein the pieces to be drawn are held in gripping jaws mounted on a movable head, and are pushed by force into the dies or draw plates, as by means of a horizontally sliding carriage which carries the head carrying the gripping jaws, this device being characterized by the fact that control means are provided for the purpose of causing, at the end of the return stroke of the gripping head to its initial position, the temporary raising of the gripping head for the insertion of new metal bars or pieces to be drawn, this latter operation being performed during the drawing of the metal pieces which had been previously inserted. The means which may be used to thus raise the gripping head include a pneumatic jack with vertical thrust disposed at a position below the base of the machine, and the head of this jack may be elevated to engage the gripping head and push it upward when the gripping head is in a position over the jack.

The present invention will be understood from the following description by reference to the accompanying drawings, which show the apparatus mounted at one end of a drawing bench for the simultaneous drawing of three metal bars, and embodying the device according to the present invention, and in which drawings:

Fig. 1 is a longitudinal sectional view of the drawing apparatus at the moment when the Fig. 3 is a view of the drawing bench in trans: verse section, taken on the plane III-III of Fig. 2; v

Fig. 4 is a view of the drawing bench taken in section on the plane IV-IV of Fig. 3; and

Fig. 5 is a circuit diagram of the electric circuits for control of the drawing apparatus by electrically controlled valves of the pneumatic or hydraulic actuating devices and the connecting conduits. v

Figs. 6 and 7 show for two difierent operating positions details of the stirrup and the locking bolt and its flange,

Fig. 8 is a detail in longitudinal section of the gripping head and control jack, and

Fig. 9 is a transverse section taken on the line IXIX of Fig. 8.

Referring to the drawings, the apparatus is mounted on a base 8 which is rigidly connected to the support 9 supporting the drawing bench on which the die stock block is mounted. A die stock block is shown at 23, carrying dies 23a, 23a in the prolongation of the drawing bench.

Beneath the base 8 there is mounted a pump l, which may be a hydraulic pump, and which is driven by an electric motor 2. The fluid output of pump l is delivered by pipes, which include control valves, to the two piston control cylinders or press pots 3 and 4 mounted on the base 8 on the respective sides 'of the remote end of the base; the two pistons 5 and fi operating in these cylinders 3 and 4, push out or pull back a horizontally sliding carriage T which is guided along the length of the two lateral edges of base 8 by the two horizontal rails24, 24, which are best shown in Fig. 3.

On the front part of this sliding carriage I, there is fixedly mounted a vertical slide which slidingly receives a gripping head I 0 for gripping the metal bars l8 which are to be drawn, as shown in Figs. 3 and 4. This head H) can slide vertically in a slide mountedon carriage l, and, as shown, the jack I I, in this case, can cause this vertical movement of the head II] when head It! is in a position over jack'l l, by pushing upwardly against head Ill. The slide 1 with gripping head It and control jack H are shown in longitudinal section in Fig. 8, and in Fig. 9 are shown in transverse section taken on the plane IXIX of Fig. 8.

The metal bars l8 to be drawn are gripped in the interior of the head Ill by sets of jaws l2 in the shape of wedges (Figs), whose small ends are pointed in the? direction opposite to the pushing movement of the sliding carriage I. At

the time of the gripping of the bars I8 to be drawn, these jaws I2 are positioned wedged against the latter by the surfaces I of a corresponding slope of gripping head III.

The unit for control of the gripping or the releasing of each of the sets of jaws I2 on the bars I8, is, for each bar, an individual pneumatic cylinder I3. In the operation .of...each of..such cylinders I3, the wedge-ajaws I2. are: fixed; ona stirrup I4, which moves vertically with head I0 and which can be pushed horizontally by the end of the rod of the piston I3a of the cylinder I3 when it moves to the right underapneumatic: control. In the position of the opening of the jaws I2 and during the steady-'operation'otthe:' drawing bench during actualldrawirig thejne. dividual stirrup I4 can be locked "automatically in the upper position of grippingheadrlfiiibyu' the locking element or bell crank leverwlfi, as. shown in full lines in Fig.2. There is an'indi' vidual element I5 for eachbar, which is of bent shape. and can- :p-ivjot about it's apex 25 which is fixed on-ananglemr bracket 26 mountedon the die stock block 23. It is the flange 24b at the end or" 'i the:=upper' -horizontal' part 2 4a of thisilocking element I-SWhich hooks'onto the stirrup I4; while' the.lower vertical"partof locking element or bell crank-L4 51' two --1;io1:tionsforming a knuckle. jointzpivoted at 2 ligand-its extreme bottom-" por- 7 tion: :onleg I a terminates :-in .the teat 2 I' while-hyits lateral projection 22 it bears against themdiesto'ckiblock 23fas shownespeciallyain Figs. '6,-' 7

The action: ofltheilo'cking element' or bell crank I5 is supplemented by a manually. operable lever I ei-which'is blockedaduring.iautomatic. operation by bell crankilfi: This manuall-yzoperated :levera I 5; cam-serve forrstartinge-upt the machine; at the time of the first drawing operation, or in case of bIEaICIIOWIITOf automaticnoperation;

Belowthe grippingi j aws: I 2,3 the gripping .head;

I 9' carriesthree'=recesse hpieces121 (Fig; 3); at the bottom of:whose:.-recessess thet-three 'bars;.:l8 lie simultaneously during: the -.-actual-1 operation .of'.

their beingsdrawm; after thewhavebeen inserted. in. the: dieandzreleasedifromsthe jaws T! 2.1

The 'grippingihead. .I I!- canibetentirelywithdrawn;'7"

fromzits. position-Lin theislidingwarriagefl by =liftf-; ingsit by handless.-:IT.-; Thi'semakes: possible-the; starting.:into:operation:ofthe;drawingebenchfwithl one; two; orznthree sbars; according to :require-i ments,;or the completegstoppingnf the action of:

thergrippingiheadzby liiting out-'allithetthree sets".

of wedge'jaws:

Referringto F'ig;;.':5,i-tl'ie ccylindersxii and 4 for: the-:advance 'and returniofithez' horizontal sliding: carriage" 'I, thelsjaclci I I:-;forr.raising1the;head' I I13 I for gripping the bars I8, and the .FIJIlGlllIlLtlC' cylinders I3 forrfcausing thergrippingiand the release of the jaws iii 2- by :stirrupri 4;:can-be; {OOH-,- trolledrby the means pfzgelectrica'llyscontrolled valveszi InrFigl fielthere is;shown: atz3ilf the:elec-: trically -controlled. .valve for forward horizontal movement .of;thezslidingiicarriagea II with' its control electroemagnet '30! iactuated by relay 4 I, and, 1 atv 3 I}, .theredsshowrrfthe.electrically;controlled valve for-the; return-imovementa of sliding carriage. I with its control .electro-magnetei' actuated by'relayg45i A1732 is shown the-electrically controlledjvalve for-the control of the raising of the head CI 9 by jackizl I: ;withi.the corresponding 1 control electro-magnet actuated by relay 46. The electrically 71 controlled iwvalve 33 is for causing, through cylinder"! 3, :the; pressing together ;of.- the, jaws I2" and :hasra control: electro-magnet; 33 and: the electrically controlled :vaive- '3 4; is :for re-.- leasing these -jawsand. hasiar control .electro-ma-ge v net;3 4!: actuated .bmelaysflr; .Atefiiis showngthea high pressure pump, and 36 is the high pressure control cylinder for valves so and 34. 37 and 38 are shut off valves, and 39 and 4B are unions.

The apparatus which has been described operates as follows:

At the time of starting up the drawing operation andmoyement of the..bench,.,with. no bars I8 in=place,=.theagripping head I0 is assumedto be in the upper position shown in Fig. 2, having -10 .been raised to that position by the jack II, and

the locking element or bell crank I5 is in closed 1ocking;position,: ass-shown in full lines in Fig. 2. Compressed air is then sent, by manual control of-valv'e'33i (Fig.3;5), into the three cylinders I 3 in the.di rection?to.,.cause closing of the wedge jaws I2 by action on stirrups I4, but for each one of thesevcylinders; thiseclosing efiect is prevented by the corresponding locking bell crank i5, since the stirrup I4, the jaws I2, and the piston I311 at this moment form an integral unit locked togeth'erby bell crank l 5 by its terminal flange 24b. The operator then feeds intoplace three-new bars -lifi- -which are -to-be-drawn, inserting each of them. into the-wedge jaws I2 and pushing them in until-the bar comes to push against the-corresponding terminal teat 'ZI of bellcrank IE-q Then, the lower portion-49 'ofeachbellcrank 25-- swin'gs whilbearing by proj-ection 22 against the die stock block 23;which drives-thebreak ofthe knuckle joint aboutits -pivot'- 2 ii. The upper part 24UOf the bell brank I5then pivots upwardly aboutx'th-ez pivot-2 5' and thus, its term-inal flange- Mbi ;is freed from thworresponding stirrup I 4.- The released stirrup I4 movesto the right and immediatelyuthe wedge' jaws I Z' 'aregripped on thesrespective'bars.:Imbythe displacement of thepressure piston I3mtciward the right, since the cylinders are already under pneumatic p1=essure.-= The operator thennbleedsthefiack- I I bymanually' opening .valve w 1(Eigi-9)', and the-gripping headdescends; carrying. with '.'it2ithe -bars "I 8 in the jaws.:I2.; Asisoonwas: the head ii! reaches-.its lowest'position:restingwnebase 3 Ff-g ll, it actuateszthroughrhead :I I '7 of jack I I, a relay ii which" initiates operation 'Of'fthe; cylinder 3" and 4, by thezoutput: of pump; I and thebars :I 8 are pushed horizontally". to thee leftttoward the draw plates or-dies:23aiorrtblockszwby the forward strokeof slidingi icarriagei 'Iff'on": which the head iii isw mounted; V

Whenathezsliding carriage '1 arrives at the: end T of its: forward-'stroker-inzthe position farthest'to theule'ft, asi'fshown ini:Fig..-: 1, i it :then :acts on 1 a contactzof a :relaya42 zwhichcauses the sending of: compressed ;air;:into the;.individual pneumatic vcylinders-d3:1inrtheuidirection: to. cause, by dis:-

placement .of:stirrnp s :I 4 -iopeningof the gripping. wedge jaws :I2,.Ethat is say, their displacement toithe lefti .At'the samei' timegthe locking ele'-- ments :orrbell crank's::i5:;Iarerzautomatically re;-

turned by any suitable meanscsuchas a recall direction to cause? return ;of the sliding carriage.

I to the right. The rippingizheadzifl mountecl; on carriage 'I returnsetotheposition or the; vertical axis ottheehead "of jack- During the;v time .of .this. operation, the; carriage of. the: draw;-

, -ing bench has seized the barsx-Isiianchtheidraw ing operation itself commences, and bars l8 are pulled through dies 23a.

Upon arriving at the right end of its return stroke, the sliding carriage I, by a contact of a relay 46, causes again the lifting of the gripping head II by action of the jack 1!, which entirely disengages the Wedge jaws l2 from the bars Id which are then in the course of being drawn. These bars then lie in the recessed pieces 21 provided below the wedge jaws l2 of head 19.

When the gripping head l0 arrives at its highest position, it looks itself in the position for holding the wedge jaws 12 open by the terminal flange 24b of the respective locking elements or bell cranks I5, latching stirrup I4.

The operating cycle of the apparatus can then recommence. However, the dropping of the jack H will automatically be caused as long as the drawing bench functions, since, as soon as the bars I8 which are in the course of being drawn have been released from the head upon their coming out of the draw plate or die 23a of block 23, a relay causes the operation of the jack I! into lowered position, for example the relay 4'! which is actuated by the displacement downward of the end of the one of bars l8 upon its coming out of the die.

It will be apparent to those skilled in the art that my invention may be modified or adapted to meet particular conditions, and all such modifications which are within the scope of the ap pended claims I consider to be comprehended within the spirit of my invention.

What is claimed is:

1. In a device for feeding metal bars into metal working apparatus, a carriage, a base comprising a track along which said carriage may be horizontally linearly displaced, said track having a first end at a metal working position, a gripping head, a vertical slide fixedly carried on said carriage and wherein said head is slidably mounted, a jack mounted on said base and having a vertically displaceable shaft, said jack being positioned so that its shaft is in register with said gripping head when said carriage is in its position at the second end of said track remote from said first end thereof, displacing means adapted to displace said carriage along said track from one end thereof to the other, gripping jaws comprised in said gripping head and adapted to grip metal bars, gripping control means for causing opening and closing of said gripping jaws, locking means adapted to hold said gripping control means in a first position to retain said jaws open, said locking means comprising terminal means positioned adjacent said first end of said track, said locking means being so mounted that upon impact of a bar upon said terminal means said locking means releases said gripping control means from its said first position into a second position to close said jaws, and means comprising a first relay and actuating circuit and contacts therefor actuatable upon arrival of said carriage at the said first end of said track to cause said locking means to hold said gripping control means in its first position and to cause said gripping control means to open said jaws.

2. A device according to claim 1, and return displacement means comprising a second relay and actuating circuitv and contacts therefor, said means actuatable upon arrival of said carriage at the said first end of said track being arranged to actuate said return displacement means, and said return displacement means being adapted when so acted upon to cause said displacing means to return said carriage to said second end of said track.

3. A device according to claim 1 and return displacement means comprising a second relay and actuating circuit and contacts therefor, said means actuatable upon arrival of said carriage at the said first end of said track being arranged to actuate said return displacement means, and said return displacement means being adapted when so acted upon to causesaid displacing means to return said carriage to said second end of said track, and means comprising a third relay and actuating circuit and contacts therefor actuatable by the arrival of said carriage at said second end of said track to cause said jack to then lift said gripping head into its elevated position.

4. A device according to claim 1, and means actuatable upon descent of said gripping head in said vertical slide from its upper position to its lower position to cause said displacing means to displace said carriage from said second end of said track to said first end thereof.

5. .A device according to claim 1, said locking means comprising a pivoted bell crank having an end flange on its end remote from said terminal means thereof and adapted to engage and hold said gripping control means.

J. R. TSCHUDNOWSKY.

References Cited in the file of this patent UNITED STATES PATENTS Number 

